1. Field of the Invention
The present invention relates to a focus detecting photoelectric converting apparatus for a camera, and more specifically, to a focus detecting photoelectric converting apparatus for a camera having a plurality of monitor sensors.
2. Description of the Related Art
A focus detecting photoelectric converting apparatus for use in a conventional camera includes photoelectric converting elements outputting signals corresponding to the amount of light from an object to be focus detected and a monitor sensor provided to cover the entire area of the photoelectric converting elements or detecting the storage amount of charge of the photoelectric converting elements. When the camera is directed to the object and the monitor sensor determines that the photoelectric converting elements receive a prescribed amount of light, the photoelectric converting elements terminate the charge accumulation, so that calculation of detection of focusing condition for focus adjustment is carried out based on the data thereof.
The focus detecting photoelectric converting apparatus for use in a conventional camera is structured as described above. Since one monitor sensor covers the entire area of photoelectric converting elements, when a main object to be focus adjusted is in a back-lit scene, for example, output of the monitor sensor is susceptible to the brightness of the circumference of the object. Accordingly, sufficient charge cannot be stored corresponding to the brightness of the main object and no clear contrast can be obtained due to low brightness of the main object. As a result, the camera can not focus on the main object but on the background thereof.